The expected normal value is zero at all ages
Patients who have undergone gastric banding should be aware of the following signs that may indicate falling B12 levels and warrant prompt blood testing: Neurological symptoms: Tingling, numbness, or 'pins and needles' in the hands or feet Difficulty with balance or coordination Memory problems, difficulty concentrating, or 'brain fog' Mood changes, including low mood or irritability Haematological symptoms: Persistent fatigue or weakness disproportionate to activity levels Breathlessness on mild exertion Pallor or a slightly yellowish tinge to the skin Other indicators: A sore, smooth, or inflamed tongue (glossitis) Mouth ulcers occurring frequently It is important to recognise that some of these symptoms particularly fatigue and low mood are non-specific and may overlap with other post-operative nutritional deficiencies, such as iron or vitamin D deficiency

Reasonable approaches include: Regular blood work every 3-6 months checking metabolic markers, liver function, kidney function, and lipid profiles
None of the statements here or on any of the product labels have been evaluated by the US Food and Drug Administration
A well-formulated B12 or B complex shot or drip might be exactly what your system has been missing, and for many people, the difference is noticeable within days